Possible NSW rain event 17 and 18 April 2015

Weather models appear to identify a possible rain event across inland New South Wales and Northern Victoria for the period covering 17 and 18 April 2015.

In particular, when reviewing models at the present time, it is identified that a large portion of southern and western New South Wales and the northern border regions of Victoria stretching from the Great Dividing Range north west to Broken Hill is earmarked to receive useful rains. The model posted from GFS (attached) is similar to the Bureau of Meteorologymodel in which it suggests falls within the range of 25 to 50 mm across the region with higher totals across the ranges of the Great Dividing Range.

Longer range models even suggests an east coast low forming by Monday 20 April with more rain being concentrated along the New South Wales South Coast.

If this eventuates, this could be important given that it could mark the term "The Autumn Break" meaning the first big rain event after a dry summer. Farmers rely on the Autumn break to replenish moisture into dry soils and to establish cropping lands for the new season. This year given that models are indicating an El Nino year which brings drier than normal conditions, this event if it eventuates could potentially be crucial for some of the southern farming regions of the Murray Darling Basin.

Weather forecasts are suggesting showers or rain conditions for places like Albury, Wagga Wagga, Temora, Tumut, Hay during the Friday and Saturday period from this event.

This system is delivering or has delivered a rain event along a narrow corridor of southern New South Wales and northern Victoria generally consistent with the model provided.

However, it is interesting to note just prior to crossing through southern and western New South Wales, this system delivered some unusual rainfall totals to eastern South Australia but north of the Flinders Ranges. For the 24 hours to 9 am 17/4/2015, the following occurred:-

This is remarkable for April considering this area is on the edge of the outback and within or close to the driest regions of the country.

The plot showing this is attached.

This system has pushed through Northern Victoria including the Mallee. In particular, Mildura (Not normally associated with heavy rainfall) received 15 mm of rain to 9 am 17/4/2015 then another 56.2 mm to 6.30 am 18/4/2015.

Heavy rain has been falling across North East Victoria where many areas have received around 50 mm although this is limited to the ranges and the highlands. It is known up until 6.30 am 18/4/2015 that places like Mt Hotham and Mt Buffalo has received in excess of 90 mm. Falls Creek has received 94 mm at the same time.

For places around Yarrawonga and Deliliquin, falls continue with 41.6 mm and 29 mm being recorded to 6.30 am. Even at Albury Airport a fall of 35 mm has fallen.

With rain still falling, this could be termed the Autumn break in some southern New South Wales areas given that this is a sizeable rain event over many hours and an important event given that it is soaking the soils.

There are no flood warnings in place and river levels appear to be steady for the Ovens, Kiewa and Upper Murray Rivers.

Please find attached a satellite photo of the event. The cloud mass is extensive across New South Wales and Victoria causing the event. It appears much of the western flanks of the cloud comprises thick cirrus and there is a clearing trend crossing through Central Victoria with drier air pushing through.

Much of this would be nimbostratus cloud. Its interesting to note that at Albury Airport, air temperature and dew points are 17C or close together indicating a very low cloud base.

Most areas within the hills and ranges have received reasonable totals.

Interestingly, the Bureau of Meteorology has just issued a flood watch only for the Kiewa, Ovens and Mitta Mitta as a heads up should significant stream rises occur but there is no current flooding occurring.

The system will spread further east today and it is likely rain should ease in the affected area.